Recently, a flat panel display (FPD) is gaining much interest as a focus of an advancement of multimedia technology. Thereby, a variety of flat panel displays, such as a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and OLED devices using organic light emitting diodes, have been put into practical use.
Particularly, the OLED device provides a fast response time of 1 ms or less, has low power consumption, and is a self emission type. In addition, the OLED device has a broad viewing angle, and thus is advantageous as a moving image display medium regardless of its size. Further, the OLED device can be manufactured at low temperature, be simply manufactured based on the existing active layer process technique, and thus attracts attention as a next-generation flat panel display.
The OLED device includes a first electrode, a second electrode, and an emission layer between the first electrode and the second electrode. Holes supplied from the first electrode and electrons supplied from the second electrode are bonded together in the emission layer to form the exciton, which is a pair of a hole and an electron, and the OLED device emits light by the energy generated when the exciton returns to a bottom level.
Such OLED devices have been developed to have various structures, and, among them, a white OLED device implements a white light by including red, green, and blue subpixels, or implements a white light by further including white subpixels in addition to the red, green, and blue subpixels.
Implementing a white light, however, has been problematic because inorganic films form under the emission layer of the OLED device. This causes the viewing angle characteristic and the color uniformity of the OLED device to be deteriorated. Accordingly, a better implementation of the white light would be beneficial in manufacturing an OLED with a broader viewing angle and/or better color uniformity.